A variety of vacuum cleaner filters utilizing non-woven components are known. For example, U.S. Pat. No. 2,813,596 discloses a disposable vacuum cleaner dust container that has a strong, porous wrapper of sheet material able to filter dust particles from an air stream and a liner that includes plies of creped, cellulosic wadding.
U.S. Pat. No. 3,498,031 relates to a vacuum cleaner bag containing a reinforcing and auxiliary filter insert of felt-like material, and U.S. Pat. No. 4,540,625 is concerned with a flexible composite useful in fabricating filters and having a fiber mass of a randomly oriented mixture of non-woven substrate fibers and organic polymer fibers intertwined therewith and containing solid sorptive microscopic particles disposed against the non-woven fibers to form a flexible, air permeable, absorbent fiber filter. Other examples of filters using non-woven components will be found in U.S. Pat. Nos. 3,535,855 and 4,257,791, which is a division of U.S. Pat. Nos. 4,164,400, 4,397,907 and 4,522,876.
U.S. Pat. No. 4,589,894 describes a disposable filter for a vacuum cleaner having a microfiber filter layer sandwiched between first and second outer support layers of highly porous fabric formed of synthetic fibers.
U.S. Pat. No. 4,350,727 describes a textile composite having a knitted fabric material bonded to a non-woven needled fabric material.
Corona treated meltblown materials are known in the art, particularly in the manufacture of surgical face masks. A typical corona treating system is essentially comprised of a high voltage electrode separated by an air gap from a dielectrically covered ground electrode. A meltblown web is corona treated by exposing it to a corona created by a voltage buildup which ionizes the air in the air gap through which the meltblown web is passed. In "The Evolution Of Corona Treating Electrodes" by D. Markgraf (Enercon Industries Corp.), numerous methods of corona treatment that are known in the art, such as those employing wire electrodes, threaded rod electrodes, bar electrodes, segmented metal electrodes, driven electrode rolls, quartz electrodes and ceramic electrodes are disclosed.
Although corona treated meltblown webs are known, they have not ever been employed in a vacuum cleaner bag in the manner described in the present invention.